"We found that, after eating a meal, the first fat from it enters the blood about an hour later," Fredrik Karpe, professor of metabolic medicine at Oxford University, told the UK's Sunday Times.

"By the time three to four hours have passed, most of it has been incorporated into our adipose tissue, mostly in the shorter term fat stores around our waists."

Subjects were asked to eat foods containing fatty acids before the fat was traced through the body by the researchers. It was broken down before being absorbed by the gut wall and turned into deposits called chylomicrons. Within an hour, the chylomicrons were in the blood system.

"The process is very fast," said Professor Karpe.

"The cells in the adipose tissue around the waist catch the fat droplets as the blood carries them by, and then incorporate them into the cells for storage."

The good news: the fatty tissue is only stored around the waist for a short term and can be used as energy for exercising.